Hillary Clinton's use of a private email server while secretary of state is expected to face even more scrutiny within the next few weeks, with testimony scheduled that she and her top aides won't be able to avoid.

Clinton was the only former secretary of state who declined to take part in an inspector general's investigation that resulted in a damaging report that found that Clinton, who was secretary of state from 2009 to 2013, broke federal standards with her email, leaving a security breach that could have opened material to hackers.

Key aides also stayed away from the probe, reports The Hill, but they won't be able to avoid interviews being conducted as part of a court case brought by conservative watchdogs Judicial Watch. In addition, the FBI is continuing its investigation into Clinton's emails, and Capitol Hill is not letting the matter drop.

Friday, the Democratic front-runner's former chief of staff, Cheryl Mills, was interviewed in closed-door proceedings for the Judicial Watch case.

Other key Clinton aides, such as Huma Abedin, former IT specialist Bryan Pagliano — the webmaster who set up Clinton's private email server — and other officials are expected to be called in to answer questions under oath.

Judicial Watch has been blocked from releasing video of the depositions, but it can still release transcripts. This week, the group released a transcript from its first interview, when longtime State Department employee Lewis Lukens was deposed, reports The Hill, and it plans to release other interviews as they happen.

Clinton herself may also be called in to answer questions under oath, which could add to the email controversy as her campaign moves forward.

In addition to the court case, the House Select Committee on Benghazi is also planning to release its report about the deadly 2012 attack on the Libyan diplomatic outpost, in which four people, including Ambassador Chris Stevens, were killed.

The committee has also been interested in Clinton's emails over the course of its two-year investigation, and its report could shed even more light on the communications.

But beyond the court proceedings and the Benghazi committee probe, both considered by many to be partisan-driven, the FBI's investigation could prove most damaging, as the federal agency — led by President Barack Obama-appointed director James Comey — is exploring whether she and her staff used the private server to mishandle classified information.

More than 2,000 of the emails Clinton turned over to the State Department have been determined to have been classified, including 22 "top secret" emails that were too dangerous to release.

But Clinton argues that none of the communications were marked classified when they were sent.

Abedin and Mills, along with other key Clinton aides, have been questioned by the FBI, and when Clinton's turn for questioning comes up, that could also add furor to an electorate that already have deemed the former secretary of state untrustworthy.

"All of that feeds into this overarching problem of public distrust of her," Grant Reeher, a political science professor at Syracuse University, told The Hill. "To put it in slang terms, she's got a pretty deeply held street rep at this point. This fits the street rep."

Clinton, though, continues to maintain the use of the private server was allowed, telling CNN this week that she knew past secretaries had used personal email.

However, she admitted "it was still a mistake" and she would act differently if she could go back in time.

Hillary Clinton's use of a private email server while secretary of state is expected to face even more scrutiny within the next few weeks, with testimony scheduled that she and her top aides won't be able to avoid.